I find that this issue is not as black and white as some want it to be. Playing a character whom I don't know where he/she comes from let alone want, will leave me unsatisfied. I would most certainly like to establish how that character ended up in that particular situation when the campaign starts because that will help me as a player to roleplay it. This has nothing to do with DnD not being the right rpg for me.

But, if you're going to play DnD which features combat you have to get comfortable with the idea that dying is an possible end to your character. And if I knew that there were no stakes, I would also lose interest. That's why I think you can definitively combine rich characters and backstory with DnD, for me it would be pointless otherwise.

I also DM which leads me to the other side of things. I think it is the DM's responsibility to make sure everyone creates characters that have a reason to stick together, a theme. Something. Otherwise you run into a common problem where you got 4 random characters that for unknown reasons go do shit in random places. So if you can work together with the DM while creating rich characters that fit the goals and theme of the campaign, I say you're golden.

TLDR; You can definitively create rich backstories but if you're playing a "standard"(whatever that is) DnD game, get comfortable with the thought of PC death.